The Aaron Copland Collection consists of published and unpublished music by Copland and other composers, correspondence, writings, biographical material, datebooks, journals, professional papers including legal and financial material, photographs, awards, art work, and books. Of particular interest is the correspondence with Nadia Boulanger, which extent over 50 years, and with his long-time friend, Harold Clurman. Other significant correspondents are Leonard Bernstein, Paul Bowles, Benjamin Britten, Carlos Chávez, David Diamond, Roy Harris, Charles Ives, Claire Reis, Arnold Schoenberg, Roger Sessions, and Virgil Thomsom. The photographic collection of Copland's friend and confidant Victor Kraft, a professional photographer, forms part of the collection.

Digitized images along with identifying information and a narrative introduction are also available through the Library of Congress Web site under the title: The Aaron Copland Collection at http://hdl.loc.gov/loc.music/collmus.mu000006.